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Bucharest, Romania

Duta L.,Romanian National Institute for Lasers, Plasma and Radiation Physics | Dorcioman G.,Romanian National Institute for Lasers, Plasma and Radiation Physics | Popescu A.C.,Romanian National Institute for Lasers, Plasma and Radiation Physics | Mihailescu I.N.,Romanian National Institute for Lasers, Plasma and Radiation Physics | And 6 more authors.
Optoelectronics and Advanced Materials, Rapid Communications | Year: 2012

We report on the synthesis of electrode layers by Pulsed Laser Deposition technique. We selected Nickel Oxide-8Yttria-Stabilized Zirconia as anode, La0.6Sr0.4Co0.2Fe0.δOs-B perovskite material as cathode, and Yttria doped (Ceria-a Alumina) as electrolyte. We studied electrode structure (average grain size, porosity, and grain shape), the deposition uniformity and electrode-electrolyte interfaces. The electrodes were investigated in terms of morphology (Scanning Electron Microscopy) and composition (Energy Dispersive X-ray Spectroscopy). The initial powder and the synthesized cathodes have been investigated superficially and in bulk by Mössbauer spectroscopy, in order to detect and analyse local properties. We identified the conditions for electrode layer synthesis in respect with porosity, composition, and mean grain size.

Galca A.C.,National Institute of Materials Physics Bucharest | Stancu V.,National Institute of Materials Physics Bucharest | Husanu M.A.,National Institute of Materials Physics Bucharest | Dragoi C.,National Institute of Materials Physics Bucharest | And 4 more authors.
Applied Surface Science | Year: 2011

The paper presents the influence of pulsed laser deposition (PLD) parameters on the structural and optical properties of PZT thin films grown on platinum substrate. X-ray diffraction (XRD), spectroscopic ellipsometry (SE) and X-ray photoelectron spectroscopy (XPS) are used to determine the thin film properties. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) are employed to get additional information. By changing the distance between target and substrate, different crystalline orientations of PZT are obtained. The thin film thickness and its roughness, as well as the refractive index are also influenced by the chosen distance. © 2011 Elsevier B.V. All rights reserved.

Voicu G.,Polytechnic University of Bucharest | Dogaru I.,Polytechnic University of Bucharest | Melita D.,Polytechnic University of Bucharest | Mesterca R.,Polytechnic University of Bucharest | And 12 more authors.
Journal of Nanoparticle Research | Year: 2015

This paper investigates the antimicrobial potential of nanostructured mesoporous silica (NMS) functionalized with essential oils (EOs) and antibiotics (ATBs). The NMS networks were obtained by the basic procedure from cetyltrimethylammonium bromide and tetraethyl orthosilicate in the form of granules with diameters ranging from 100 to 300 nm with an average pore diameter of 2.2 nm, as confirmed by the BET–TEM analyses. The Salvia officinalis (SO) and Coriandrum sativum (CS) EOs and the streptomycin and neomycin ATBs were loaded in the NMS pores. TG analysis was performed in order to estimate the amount of the entrapped volatile EOs. The results of the biological analyses revealed that NMS/SO and NMS/CS exhibited a very good antimicrobial activity to an extent comparable or even superior to the one triggered by ATB, and a good in vitro and in vivo biocompatibility. Due to their regular pores, high biocompatibility, antimicrobial activity, and capacity to stabilize the volatile EOs, the obtained NMS can be used as an efficient drug delivery system for further biomedical applications. © 2015, Springer Science+Business Media Dordrecht.

Grumezescu V.,Polytechnic University of Bucharest | Grumezescu V.,Romanian National Institute for Lasers, Plasma and Radiation Physics | Holban A.M.,University of Bucharest | Grumezescu A.M.,Polytechnic University of Bucharest | And 8 more authors.
Biofabrication | Year: 2014

Due to their persistence and resistance to the current therapeutic approaches, Staphylococcus aureus biofilm-associated infections represent a major cause of morbidity and mortality in the hospital environment. Since (+)-usnic acid (UA), a secondary lichen metabolite, possesses antimicrobial activity against Gram-positive cocci, including S. aureus, the aim of this study was to load magnetic polylactic-co-glycolic acid-polyvinyl alcohol (PLGA-PVA) microspheres with UA, then to obtain thin coatings using matrix-assisted pulsed laser evaporation and to quantitatively assess the capacity of the bio-nano-active modified surface to control biofilm formation by S. aureus, using a culture-based assay. The UA-loaded microspheres inhibited both the initial attachment of S. aureus to the coated surfaces, as well as the development of mature biofilms. In vitro bioevalution tests performed on the fabricated thin films revealed great biocompatibility, which may endorse them as competitive candidates for the development of improved non-toxic surfaces resistant to S. aureus colonization and as scaffolds for stem cell cultivation and tissue engineering. © 2014 IOP Publishing Ltd.

Rasleanu D.,Ovidius University | Ciupina V.,Ovidius University | Prodan G.,Ovidius University | Lungu C.P.,National Institute for Laser, Plasma and Radiation Physics | And 2 more authors.
Journal of Optoelectronics and Advanced Materials | Year: 2013

In this paper we present an approach of the obtaining and study of nanostructured materials with special resistive magnetic properties. The Cu and Co thin films are grown by a physical thermionic vacuum arc method (TVA). Successive layers of Cu and Co were deposited on ceramic substrates using tungsten crucibles each containing Cu and Co metals, respectively. The morphological and structural investigations were achieved by means of electron microscopy technique: TEM (Philips, CM120ST). The compositional analysis of the films was performed by an X-ray spectroscopy and correlated to the electrical resistance.

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